So, you have two sorts of smiles: A real happiness smile a Duchenne smile--called--also known as the Duchenne smile, and then a Pan Am smile, or greeting smile.

所以，有两种微笑：,真正开心的微笑,杜乡式微笑，泛美式微笑，或问候式微笑。

耶鲁公开课 - 心理学导论课程节选

So, there are other things we know about smiles.

所以，我们知道了关于微笑的其他事情。

耶鲁公开课 - 心理学导论课程节选

So, if you smile at somebody, and you just hate their guts but you want to smile at them, it's--unless you're quite gifted it's difficult to fake a really good, really happy smile.

所以，你对某人微笑，你很讨厌他们，但你要对他们微笑，除非你很有天赋,很难去假笑，伪装真正的微笑。

耶鲁公开课 - 心理学导论课程节选